Lactobacillus acidophilus attenuates Salmonella-induced intestinal inflammation via TGF-ß signaling.

BACKGROUND: Salmonella is a common intestinal pathogen that causes acute and chronic inflammatory response. Probiotics reduce inflammatory cytokine production and serve as beneficial commensal microorganisms in the human gastrointestinal tract. TGF-ß (transforming growth factor ß)/SMAD and NF-κB signaling play important roles in inflammation in intestinal cells. However, the involvement of the signaling in regulating inflammation between Salmonella and probiotics is not fully understood. METHODS: L. acidophilus and prebiotic inulin were used to treat human intestinal Caco-2 cells prior to infection with Salmonella. The cells were harvested to examine the cytokines and MIR21 expression with immunoblotting and real-time PCR. NF-κB and SMAD3/4 reporter vectors were transfected into cells to monitor inflammation and TGF-ß1 signaling, respectively. RESULTS: In this study, we showed that the probiotic L. acidophilus decreased Salmonella-induced NF-κB activation in human intestinal Caco-2 cells. Expression of the inflammatory cytokines, TNF-α and IL-8, in L. acidophilus-pretreated cells was also significantly lower than that in cells infected with Salmonella alone. Moreover, TGF-ß1 and MIR21 expression was elevated in cells pretreated with L. acidophilus or synbiotic, a combination of inulin and L. acidophilus, compared to that in untreated cells or cells infected with S. typhimurium alone. By contrast, expression of SMAD7, a target of MIR21, was accordingly reduced in cells treated with L. acidophilus or synbiotics. Consistent with TGF-ß1/MIR21 and SMAD7 expression, SMAD3/4 transcriptional activity was significantly higher in the cells treated with L. acidophilus or synbiotics. Furthermore, TGF-ß1 antibody antagonized the SMAD3/4 and NF-κB transcriptional activity modulated by L. acidophilus in intestinal cells. CONCLUSION: Our results suggest that the TGF-ß1/MIR21 signaling pathway may be involved in the suppressive effects of L. acidophilus on inflammation caused by S. typhimurium in intestinal Caco-2 cells.

Selective cytotoxic effects of low-power laser irradiation on human oral cancer cells.

BACKGROUND AND OBJECTIVES: Low-power laser irradiation (LPLI) is known to regulate cell proliferation and migration in clinical use. Recent studies have shown that LPLI induces cell death in some certain types of cancer cell lines. However, the cytotoxic selectivity of LPLI for cancer cells is not fully understood. The aim of this study was to compare the cytotoxic effects of LPLI in both human oral cancer OC2 cells and normal human gingival fibroblast (HGF) cells. MATERIALS AND METHODS: LPLI at 810 nm with an energy density from 10 to 60 J/cm(2) was used to irradiate human oral cancer OC2 cells and normal HGF cells. RESULTS: We found that LPLI significantly diminished cell viability of human oral cancer OC2 cells due to cell cycle arrest at the G1 phase and the induction of cell death but that it had no or little effects on cell cycle progression and death in normal HGF cells. Moreover, the production of reactive oxygen species (ROS) and the loss of mitochondrial membrane potential (MMP) were elevated in human oral cancer OC2 cells compared with the un-irradiated cells. In contrast, these effects remained unchanged in normal HGF cells after exposure to LPLI. LPLI also induced apoptosis in caspase-3 dependent manner in human oral cancer OC2 cells, a mode of action that could be mediated by ROS and mitochondrial damage. CONCLUSION: Our findings imply LPLI might be a potential therapy for oral cancers.

Investigation of carvedilol-evoked Ca²+ movement and death in human oral cancer cells.

The effect of carvedilol on cytosolic free Ca²âº concentrations ([Ca²âº](i)) in OC2 human oral cancer cells is unknown. This study examined if carvedilol altered basal [Ca²âº](i) levels in suspended OC2 cells by using fura-2 as a Ca²âº-sensitive fluorescent probe. Carvedilol at concentrations between 10 and 40 µM increased [Ca²âº](i) in a concentration-dependent fashion. The Ca²âº signal was decreased by 50% by removing extracellular Ca²âº. Carvedilol-induced Ca²âº entry was not affected by the store-operated Ca²âº channel blockers nifedipine, econazole, and SK&F96365, but was enhanced by activation or inhibition of protein kinase C. In Ca²âº-free medium, incubation with the endoplasmic reticulum Ca²âº pump inhibitor thapsigargin did not change carvedilol-induced [Ca²âº](i) rise; conversely, incubation with carvedilol did not reduce thapsigargin-induced Ca²âº release. Pretreatment with the mitochondrial uncoupler carbonylcyanide m-chlorophenylhydrazone (CCCP) inhibited carvedilol-induced [Ca²âº](i) release. Inhibition of phospholipase C with U73122 did not alter carvedilol-induced [Ca²âº](i) rise. Carvedilol at 5-50 µM induced cell death in a concentration-dependent manner. The death was not reversed when cytosolic Ca²âº was chelated with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA/AM). Annexin V/propidium iodide staining assay suggests that apoptosis played a role in the death. Collectively, in OC2 cells, carvedilol induced [Ca²âº](i) rise by causing phospholipase C-independent Ca²âº release from mitochondria and non-endoplasmic reticulum stores, and Ca²âº influx via protein kinase C-regulated channels. Carvedilol (up to 50 µM) induced cell death in a Ca²âº-independent manner that involved apoptosis.

Paroxetine-induced Ca2+ movement and death in OC2 human oral cancer cells.

The effect of the antidepressant paroxetine on cytosolic free Ca2+ concentrations ([Ca2+]i) in OC2 human oral cancer cells is unclear. This study explored whether paroxetine changed basal [Ca2+]i levels in suspended OC2 cells by using fura-2 as a Ca2+-sensitive fluorescent dye. Paroxetine at concentrations between 100-1,000 microM increased [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was reduced by 50% by removing extracellular Ca2+. Paroxetine-induced Ca2+ influx was inhibited by the store-operated Ca2+ channel blockers nifedipine, econazole and SK&F96365, and protein kinase C modulators. In Ca2+-free medium, pretreatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin abolished paroxetine-induced [Ca2+]i rise. Inhibition of phospholipase C with U73122 did not alter paroxetine-induced [Ca2+]i rise. Paroxetine at 10-50 microM induced cell death in a concentration-dependent manner. The death was not reversed when cytosolic Ca2+ was chelated with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. Propidium iodide staining suggests that apoptosis plays a role in the death. Collectively, in OC2 cells, paroxetine induced [Ca2+]i rise by causing phospholipase C-independent Ca2+ release from the endoplasmic reticulum and Ca2+ influx via store-operated Ca2+ channels in a manner regulated by protein kinase C and phospholipase A2. Paroxetine (up to 50 microM) induced cell death in a Ca2+-independent manner.

Evaluation on the movement of endosseous titanium implants under continuous orthodontic forces: an experimental study in the dog.

OBJECTIVES: The purpose of this study was to evaluate the movement of pure titanium implants under different continuous forces in the edentulous alveolar ridge. MATERIAL AND METHODS: Four pairs of titanium implants were inserted into the right maxillary and mandibular post-extraction edentulous ridge of the experimental dog. Three different levels of continuous force (100, 200, and 500 g) were loaded onto three pairs of adjacent implant abutments using a memory Ni-Ti coil spring for up to 6 months and the remaining two implant abutments as the control group received no force. The positions of implant abutments were observed and the distances between the implants abutment at the top, middle and base levels were measured at the 0th, 2nd, 3rd, 6th and 8th month of the follow-up period. RESULTS: There was no significant change in the distances between adjacent abutments loaded with 100 or 200 g continuous forces throughout the entire study period. However, significantly more movement of implant abutments was noted in the 500 g pair after the 3rd month of loading when compared with the 200 or the 100 g pair (both P < 0.001). This change further increased at the 6th month (P < 0.001, 0.01, respectively). Moreover, the difference in the measurements at the top, middle and base level indicated that the two adjacent implants moved in a tipping manner in the 500 g pair after 3 and 6 months of loading. CONCLUSION: The osseointegrated implants remained stable and rigid with a pulling force of 100 and 200 g after 6 months of loading. However, when the force reached 500 g, the implants moved in an inward-tipping pattern. The results suggested that endosseous titanium implants might not necessarily be rigid anchorages under all circumstances.

Rapid diagnosis of bacterial meningitis using a microarray.

BACKGROUND/PURPOSE: Microarrays, or biochips, are a new technology that can allow rapid detection of bacterial genetic materials. To explore their practical applications, we compared use of a microarray for the diagnosis of bacterial meningitis with the traditional blood and cerebrospinal fluid (CSF) culture methods. METHODS: Samples from 50 patients with suspected bacterial meningitis were analyzed by microarray and by traditional blood and CSF cultures. RESULTS: Among all samples, 11 were positive by microarray analysis, seven were positive by CSF bacterial culture and six were positive by blood culture. CSF pleocytosis was found in 26 patients. Of these, eight were positive by microarray analysis, seven were positive by CSF culture and five were positive by blood culture. The percentage of positive results from microarray analysis was 22%, compared to 14% by CSF culture and 12% by blood culture. The CSF bacterial culture method had the highest positive predictive value and specificity (both 100%). The sensitivity of microarray analysis was higher (30.8%) than that of CSF and blood cultures (26.9% and 19.2%). All three methods had a similar negative predictive value in the range of 52.3-55.8%. Of the 11 microarray positive samples, four were identified successfully in CSF culture (36.4%) and three samples were identified in blood culture (27.2%). One of the microarray positive samples was diagnosed as a polymicrobial infection (9%), and the rest were monomicrobial infections. CONCLUSION: The microarray method provides a more accurate and rapid diagnostic tool for bacterial meningitis compared to traditional culture methods. Clinical application of this new technique may reduce the potential risk of delay in treatment.

Correlation Between Resonance Frequency Analysis and Bone Quality Assessments at Dental Implant Recipient Sites.

PURPOSE: To evaluate whether primary implant stability could be used to predict bone quality, the association between the implant stability quotient (ISQ) value and the bone type at the implant site was evaluated. MATERIALS AND METHODS: Ninety-five implant sites in 50 patients were included. Bone type (categorized by Lekholm and Zarb) at the implant site was initially assessed using presurgical dental radiography. During the preparation of the implant site, a bone core specimen was carefully obtained. The bone type was assessed by tactile sensation during the drilling operation, according to the Misch criteria. The primary stability of the inserted implant was evaluated by resonance frequency analysis (RFA). The ISQ value was recorded. The bone core specimen was then examined by stereomicroscopy or microcomputed tomography (micro-CT), and the bone type was determined by the surface characteristics of the specimen, based on Lekholm and Zarb classification. Agreement between the bone quality assessed by the four methods (ie, presurgical radiography, tactile sensation, stereomicroscopy, and micro-CT) was tested by Cohen's kappa statistics, whereas the association between the ISQ value and the bone type was evaluated by the generalized linear regression model. RESULTS: The mean ISQ score was 72.6, and the score was significantly influenced by the maxillary or mandibular arch (P = .001). The bone type at the implant sites varied according to the assessment method. However, a significant influence of the arch was repeatedly noted when using radiography or tactile sensation. Among the four bone-quality assessment methods, a weak agreement existed only between stereomicroscopy and micro-CT, especially in the maxilla (κ = 0.469). A negative association between the ISQ value and the bone type assessed by stereomicroscopy or by micro-CT was significant in the maxilla, but not in the mandible, after adjustments for sex, age, and right/left side (P = .013 and P = .027 for stereomicroscopy and micro-CT, respectively). CONCLUSION: The ISQ value was weakly associated with the bone type when assessed by stereomicroscopy or micro-CT in the maxilla. Caution is necessary if RFA is used as a tool to evaluate bone quality at the implant site, especially in the mandible.

Vimentin is a potential prognostic factor for tongue squamous cell carcinoma among five epithelial-mesenchymal transition-related proteins.

We aimed to investigate the association of the expression levels of five epithelial-mesenchymal transition (EMT)-related proteins (Snail, Twist, E-cadherin, N-cadherin, and Vimentin) with tumorigenesis, pathologic parameters and prognosis in tongue squamous cell carcinoma (TSCC) patients by immunohistochemistry of tissue microarray. The expression levels of Snail, E-cadherin, N-cadherin and Vimentin were significantly different between the tumor adjacent normal and tumor tissues. In tumor tissues, lower E-cadherin and higher N-cadherin levels were associated with a higher grade of cell differentiation, advanced stage of disease, and lymph node metastasis. However, higher Vimentin expression was associated with poor cell differentiation and lymph node metastasis. Patients with low E-cadherin expression had poor disease-specific survival (DSS). Conversely, positive N-cadherin and higher Vimentin expression levels were associated with poor DSS and disease-free survival. Notably, our multivariate Cox regression model indicated that high Vimentin expression was an adverse prognostic factor for DSS in TSCC patients, even after the adjustment for cell differentiation, pathological stage, and expression levels of Snail, Twist, E-cadherin, and N-cadherin. Snail, E-cadherin, N-cadherin, and Vimentin were associated with tumorigenesis and pathological outcomes. Among the five EMT-related proteins, Vimentin was a potential prognostic factor for TSCC patients.

Interfacial analysis of porcelain fused to high-palladium alloy with different observation methods.

BACKGROUND/PURPOSE: In a previous fractural study of implant-supported crowns, it was found that the palladium-silver crowns possessed the highest fracture force. The ceramic-metal interface was examined to explain its high resistance to fracture. MATERIALS AND METHODS: Palladium-silver crowns with the morphology of a maxillary second premolar were prepared following standard dental laboratory procedures. Crown specimens were compressed vertically in the center of the occlusal surface until fracture, using a universal testing machine. The fractured surfaces were examined using scanning electron microscopy combined with energy dispersive X-ray spectroscopy to determine the failure mode. The ceramic-metal interface of the crown was examined with electron probe microanalysis. Additionally, sheet specimens with a dimension of 10 × 9 × 4 mm3 were prepared to examine the surface morphology and composition of palladium-silver alloy after oxidation and porcelain-fused-to-metal firing cycles. RESULTS: The average fracture force was 1425 ± 392N. Analyses with scanning electron microscopy combined with energy dispersive X-ray spectroscopy revealed that the failure mode was cohesive within the ceramic layer. Electron probe microanalysis micrographs indicated that Sn and In were found to distribute only on the alloy side of the ceramometal crown. Energy dispersive X-ray spectroscopy analysis and electron probe microanalysis micrographs confirmed that ZnO had diffused into the ceramic phase. CONCLUSION: In2O3, SnO2, and ZnO were found along the interface; the presence of these oxides at the boundary promotes ceramic-metal adhesion, and this resulted in cohesive failure of the ceramic layer. ZnO was found to diffuse into the ceramic phase, and it is suggested to be beneficial for high fracture resistance in the present study.

Effects of Salvia miltiorrhiza ethanolic extract on lipopolysaccharide-induced dental alveolar bone resorption in rats.

BACKGROUND/PURPOSE: Salvia miltiorrhiza (SM) Bunge (Labiatae/Lamiaceae; common name danshen) is a Chinese medicine that improves blood circulation and inhibits inflammatory response. Thus, it is used for the treatment of cardiac diseases and inflammation. In this study, we aimed to evaluate the effect of an ethanolic extract of SM (SME) on the dental alveolar bone resorption induced by bacterial lipopolysaccharide (LPS) in rats. MATERIALS AND METHODS: An ethanolic extract was prepared from roots of SM. The major constituents of this extract were determined by high-performance liquid chromatography. The activity of the extract was evaluated in a rat model in which the dental alveolar bone resorption was induced by injection of bacterial LPS into the palatal gingiva around the maxillary molar teeth. The effect of SME on the bone resorption was studied by histologic and histomorphometric analysis. RESULTS: The number of osteoclasts and the percentage of osteoclasts covering the alveolar bone surfaces were significantly increased in the LPS group compared with those in the phosphate-buffered saline (PBS) group. The number and percentage of the osteoclasts on the bony surfaces were significantly reduced in the SME group in comparison with the LPS group, although it was still higher than the numbers observed in the PBS group. CONCLUSION: Because SME reduced bone resorption caused by the injections of bacterial LPS in rats, we suggest that SME might have a protective effect on dental alveolar bone resorption in periodontitis.

Bifid mandibular canals and their cortex thicknesses: A comparison study on images obtained from cone-beam and multislice computed tomography.

BACKGROUND/PURPOSE: High prevalence of bifid mandibular canals has been visualized with various types of computerized tomography (CT). Along the canals, a various ranged corticalization was recently reported. The depiction of the fine anatomic structures on multislice and cone-beam CT images was compared. MATERIAL AND METHODS: The presence or absence of the bifid canal was assessed on 327 images obtained by multislice CT (MSCT; n = 173) or by cone-beam CT (CBCT; n = 154), according to the configuration. The cortex thickness and distribution were also assessed. RESULTS: The prevalence of bifid canal detected by CBCT was significantly greater than that detected by MSCT (42.2% vs. 18.7% for hemi-mandibles and 58.4% vs. 30.6% for patients). Cortical thickness recorded by CBCT was significantly thinner than that recorded by MSCT (0.48 mm vs. 0.65 mm, P < 0.001); however, the distributions of corticalization detected by the two tomography methods were similar. There was a significant association of cortex thickness with CT type and corticalization degree (R 2 = 0.530, P < 0.001). CONCLUSION: Thinner cortices, but greater prevalence of bifid canals recorded by CBCT, compared to MSCT, suggests that clinicians should be cautious when using CT to interpret this fine anatomic structure.

RelA-Mediated BECN1 Expression Is Required for Reactive Oxygen Species-Induced Autophagy in Oral Cancer Cells Exposed to Low-Power Laser Irradiation.

Low-power laser irradiation (LPLI) is a non-invasive and safe method for cancer treatment that alters a variety of physiological processes in the cells. Autophagy can play either a cytoprotective role or a detrimental role in cancer cells exposed to stress. The detailed mechanisms of autophagy and its role on cytotoxicity in oral cancer cells exposed to LPLI remain unclear. In this study, we showed that LPLI at 810 nm with energy density 60 J/cm2 increased the number of microtubule associated protein 1 light chain 3 (MAP1LC3) puncta and increased autophagic flux in oral cancer cells. Moreover, reactive oxygen species (ROS) production was induced, which increased RelA transcriptional activity and beclin 1 (BECN1) expression in oral cancer cells irradiated with LPLI. Furthermore, ROS scavenger or knockdown of RelA diminished LPLI-induced BECN1 expression and MAP1LC3-II conversion. In addition, pharmacological and genetic ablation of autophagy significantly enhanced the effects of LPLI-induced apoptosis in oral cancer cells. These results suggest that autophagy may be a resistant mechanism for LPLI-induced apoptosis in oral cancer cells.

Effect of cyclosporin A on the mineral apposition rate of cementum and dentin in growing rats.

BACKGROUND: Since there is no direct information to verify whether cyclosporin A (CsA) can affect the mineralization of dental hard tissue, the formation of dentin and cementum in growing rats was recorded by labeling the mineral phase of these tissues with fluorochrome marker in this study. METHODS: After the extraction of the right maxillary molars, 30 male 3-week-old Sprague-Dawley rats were assigned to two groups. Following a 2-week healing period, the experimental rats received 30 mg/kg CsA daily for 7 weeks, while the control rats received only mineral oil. The fluorescent markers, calcein and alizarin red, were given on alternate weeks for 7 weeks. At the end of study, the mandibles were obtained and undemineralized sections were processed. Serial sections, 8 microm thick, were cut for the entire distal roots of the first molars. Five central sections were selected to determine the mineral apposition of cellular cementum and dentin at the apex and middle of root, respectively. RESULTS: The apposition rates of apical cellular cementum were significantly influenced by CsA therapy, occlusal function, and observation duration. However, the dentin apposition rates were significantly influenced by the observation intervals only. CONCLUSIONS: In this study, CsA therapy and occlusal function significantly influenced the apposition rates of apical cementum, but not the rates of mid-root dentin. Our hypothesis that CsA can induce oral hard tissue alterations, as well as gingival overgrowth, is demonstrated.

Propionibacterium acnes in the pathogenesis and immunotherapy of acne vulgaris.

Acne vulgaris, a multi-factorial disease, is one of the most common skin diseases, affecting an estimated 80% of Americans at some point during their lives. The gram-positive and anaerobic Propionibacterium acnes (P. acnes) bacterium has been implicated in acne inflammation and pathogenesis. Therapies for acne vulgaris using antibiotics generally lack bacterial specificity, promote the generation of antibiotic-resistant bacterial strains, and cause adverse effects. Immunotherapy against P. acnes or its antigens (sialidase and CAMP factor) has been demonstrated to be effective in mice, attenuating P. acnes-induced inflammation; thus, this method may be applied to develop a potential vaccine targeting P. acnes for acne vulgaris treatment. This review summarizes reports describing the role of P. acnes in the pathogenesis of acne and various immunotherapy-based approaches targeting P. acnes, suggesting the potential effectiveness of immunotherapy for acne vulgaris as well as P. acnes-associated diseases.

Effects of low-dose cyclosporin on osteogenesis of human demineralized bone grafts in a surgically created mandibular defect in rats.

BACKGROUND: Demineralized freeze-dried bone matrix (DFDBM) stimulates new bone formation; however, immune reactions from the residual antigens of prepared grafts might play a role in inducing osteogenesis. This study examined whether cyclosporine-A (CsA), an immunosuppressant, enhanced the DFDBM-induced new bone formation. METHODS: After creating a bony defect in the posterior mandible, 40 male Sprague-Dawley rats were divided into four groups of 10 each: no graft with mineral oil (control); no graft with CsA in mineral oil; DFDBM with mineral oil; and DFDBM with CsA in mineral oil (combined therapy). CsA was administered at 2 mg/kg body weight. Five rats in each group were sacrificed at days 10 and 28 and tissue samples were taken for histological examination. RESULTS: Soft tissue was observed in the defects of all animals without grafts, whereas the repaired hard tissue formed in the defects of animals with grafts. Histometery, which was performed only at day 10, revealed both DFDBM and CsA therapies produced a significant increase in the total area of repaired hard tissue. Only CsA therapy significantly increased the new bone area. Compared with the DFDBM group, the composition of the repaired hard tissue in the combined therapy group shifted; i.e., the new bone area increased but the residual particle area decreased. The cartilage formation was greater in the combined therapy group than the DFDBM group. CONCLUSION: Within the limitations of this study, we suggest that the DFDBM grafts play a major role, which could be enhanced by CsA, in the induction of new bone formation, especially at an early phase.

Periodontal status in post-menopausal osteoporosis: a preliminary clinical study in Taiwanese women.

BACKGROUND: Osteoporosis and periodontitis are common diseases affecting post-menopausal women; however, the exact relationship between the diseases is still uncertain. The purposes of this study were to examine the periodontal status in a group of type I post-menopausal women with and without osteoporosis and to elucidate the possible role of the osteoporosis in the pathogenesis of periodontal disease. METHODS: Thirty-four patients (18 in the osteoporotic and 16 in the non-osteoporotic group) were selected from 329 post-menopausal Taiwanese women who had completed radiographic measurements of spinal bone mineral density and received full-mouth periodontal examination. Periodontal measurements, including O'Leary plaque index, probing depths, clinical attachment level, and gingival recession, on 6 sites of each tooth of full mouth were examined and recorded by 1 examiner. RESULTS: Significantly greater probing depth was noted at the interproximal, but not at the facio-lingual, osteoporotic sites if compared to those non-osteoporotic sites. The depth was also significantly influenced by the examining factors of plaque accumulation, tooth location, and jaws. By individual jaw, increased attachment loss accompanied by greater probing depth and gingival recession was found at the osteoporotic sites on mandible if compared to non-osteoporotic sites. On maxilla, however, less gingival recession and attachment loss were observed at the osteoporotic sites. CONCLUSIONS: In the present study, increased attachment loss accompanied by greater probing depth and gingival recession was found at the osteoporotic sites on mandible. However, the parameters were also influenced by the examining factors of plaque accumulation, tooth location, and jaws. Therefore, we suggest that post-menopausal osteoporosis may play a role in the pathogenesis of periodontal disease, especially on the mandible, although the etiology of periodontal disease is still multi-factorial.

A high IL-4 production diplotype is associated with an increased risk but better prognosis of oral and pharyngeal carcinomas.

OBJECTIVE: Interleukin (IL)-4 is a key cytokine in humoral and adaptive immunity. This study aimed to evaluate the association of IL-4 genetic variants (-590C>T and VNTR in intron 3) with the risk and prognosis of oral and pharyngeal squamous cell carcinoma (OPSCC). DESIGN: A total of 1215 subjects, which included 623 healthy controls and 592 OPSCC cases (463 oral squamous cell carcinoma (OSCC) and 129 pharyngeal squamous cell carcinoma (PSCC) cases), were recruited. The genotypes were determined by TaqMan real-time assay and PCR-based assay. RESULTS: The IL-4 genotypes at locus -590C>T and intron 3 VNTR were not correlated with increased risk of OSCC, PSCC, and OPSCC, with the exception of early-stage OPSCC (at -590C>T: T/T vs. C/C+C/T, adjusted odds ratio (AOR)=1.42, 95% CI: 1.02-1.98; at intron 3 VNTR: RP1/RP1 vs. RP2/RP2+RP2/RP1, AOR=1.46, 95% CI: 1.05-2.04). Compared with other IL-4 diplotypes, the T,RP1/T,RP1 diplotype was associated with an increased risk of OPSCC (AOR=1.37, 95% CI: 1.03-1.81), particularly early-stage OSCC (AOR=1.43, 95% CI: 1.02-2.00), PSCC (AOR=2.35, 95% CI: 1.06-5.19), and OPSCC (AOR=1.52, 95% CI: 1.10-2.11). Interactions between the IL-4 diplotype and the alcohol drinking status were found to contribute to the risk of early-stage OPSCC (p=0.024). In addition, the T,RP1/T,RP1 diplotype was correlated with better disease-specific survival (T,RP1/T,RP1 vs. other diplotypes, adjusted hazard ratio=0.70, 95% CI: 0.50-0.97). CONCLUSION: The T, RP1/T, RP1 diplotype of IL-4 was associated with an increased risk but favourable prognosis of OPSCC.

Effect of m-3m3FBS on Ca2+ handling and viability in OC2 human oral cancer cells.

The effect of 2,4,6-trimethyl-N-(meta-3-trifluoromethyl-phenyl)-benzenesulfonamide (m-3M3FBS), a presumed phospholipase C activator, on cytosolic free Ca2+ concentrations ([Ca2+]i) in OC2 human oral cancer cells is unclear. This study explored whether m-3M3FBS changed basal [Ca2+]i levels in suspended OC2 cells by using fura-2 as a Ca2+-sensitive fluorescent dye. M-3M3FBS at concentrations between 10-60 µM increased [Ca2+]i in a concentration-dependent manner. The Ca2+ signal was reduced partly by removing extracellular Ca2+. M-3M3FBS-induced Ca2+ influx was inhibited by the store-operated Ca2+ channel blockers nifedipine, econazole and SK&F96365, and by the phospholipase A2 inhibitor aristolochic acid. In Ca2+-free medium, 30 µM m-3M3FBS pretreatment inhibited the [Ca2+]i rise induced by the endoplasmic reticulum Ca2+ pump inhibitors thapsigargin and 2,5-di-tert-butylhydroquinone (BHQ). Conversely, pretreatment with thapsigargin, BHQ or cyclopiazonic acid partly reduced m-3M3FBS-induced [Ca2+]i rise. Inhibition of inositol 1,4,5-trisphosphate formation with U73122 did not alter m-3M3FBS-induced [Ca2+]i rise. At concentrations between 5 and 100 µM m-3M3FBS killed cells in a concentration-dependent manner. The cytotoxic effect of m-3M3FBS was not reversed by prechelating cytosolic Ca2+ with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). Propidium iodide staining data suggest that m-3M3FBS (20 or 50 µM) induced apoptosis in a Ca2+-independent manner. Collectively, in OC2 cells, m-3M3FBS induced [Ca2+]i rise by causing inositol 1,4,5-trisphosphate-independent Ca2+ release from the endoplasmic reticulum and Ca2+ influx via phospholipase A2-sensitive store-operated Ca2+ channels. M-3M3FBS also induced Ca2+-independent cell death and apoptosis.

Effect of methoxychlor on Ca2+ handling and viability in OC2 human oral cancer cells.

The effect of the insecticide methoxychlor on the physiology of oral cells is unknown. This study aimed to explore the effect of methoxychlor on cytosolic Ca(2+) concentrations ([Ca(2+)](i)) in human oral cancer cells (OC2) by using the Ca(2+)-sensitive fluorescent dye fura-2. Methoxychlor at 5-20 µM increased [Ca(2+)](i) in a concentration-dependent manner. The signal was reduced by 70% by removing extracellular Ca(2+). Methoxychlor-induced Ca(2+) entry was not affected by nifedipine, econazole, SK&F96365 and protein kinase C modulators but was inhibited by the phospholipase A2 inhibitor aristolochic acid. In Ca(2+)-free medium, treatment with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) inhibited or abolished methoxychlor-induced [Ca(2+)](i) rise. Incubation with methoxychlor also inhibited thapsigargin- or BHQ-induced [Ca(2+)](i) rise. Inhibition of phospholipase C with U73122 did not alter methoxychlor-induced [Ca(2+)](i) rise. At 5-20 µM, methoxychlor killed cells in a concentration-dependent manner. The cytotoxic effect of methoxychlor was not reversed by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/AM (BAPTA/AM). Annexin V-FITC data suggest that methoxychlor (10 and 20 µM) evoked apoptosis in a concentration-dependent manner. Together, in human OC2, methoxychlor induced a [Ca(2+)](i) rise probably by inducing phospholipase C-independent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via phospholipase A(2)-sensitive channels. Methoxychlor induced cell death that may involve apoptosis.

Interaction between tumour necrosis factor-α gene polymorphisms and substance use on risk of betel quid-related oral and pharyngeal squamous cell carcinoma in Taiwan.

OBJECTIVE: Betel quid (BQ) components induce the secretion of tumour necrosis factor-alpha (TNF-α) in oral keratinocytes, which promotes oral mucosal inflammation and oral cancer. This study was carried out to evaluate the association of TNFA genetic variants (-308G>A and -238G>A) with the risk and prognosis of BQ-related oral and pharyngeal squamous cell carcinoma (OPSCC). DESIGN: A total of 403 subjects (205 cancer cases and 198 healthy controls) who habitually chewed BQ were recruited. The genotypes were determined by TaqMan real-time assays. RESULTS: G allele and G/G genotype at TNFA -308 were associated with a 1.95-fold (95%CI: 1.16-3.28, p(corrected)=0.024) and 2.28-fold (95%CI: 1.30-4.00, p(corrected)=0.008) increased risk of cancer as compared to those with A allele or A/A+A/G genotypes, respectively. In addition, G allele (p=0.080) and G/G genotype (p=0.076) at TNFA -238 were associated with a borderline but statistically significant increased risk of OPSCC. The combined G/G+G/G genotype at both loci had a 2.37-fold increased risk of OPSCC as compared to those with other combined genotypes (95%CI: 1.41-4.00, p=0.001). Interactions between combined genotypes and smoking status were also found to contribute to risk of BQ-related OPSCC. There was no association of TNFA genotypes with clinicopathologic findings or the survival of OPSCC patients. CONCLUSIONS: BQ-chewers who carry the G allele or G/G genotype in TNFA -308 may have an increased risk of OPSCC. The intensity of cigarette smoking modulates the effect of the combined TNFA genotypes on risk of BQ-related OPSCC.